Tractor excavator



0. S. SANDBERG.

TRACTOR EXCAVATOR.

APPLICATION FILED FEB. a, 19m.

1,407,486, Patented. Feb. 21, 1922.

2 SHEETS-SHEET l- 0'. s. SANDBERG.

TRACTOR EXCAVATOR.

APPLlCATlON FILED FEB-8,1919.

2 SHEETS-SHEET 21 Patented Feb. 21, 1922.

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UNHTD ATS OLOF S. SANDBERG, OF MINNEAPOLIS, MINNESOTA.

TRACTOR EXCAVATOR.

Specification of Letters Patent.

Patented Feb. 21, 1922.

Application filed February 8, 1919. Serial No. 275,913.

To all whom it may concern:

Be it known that I, 01.011 S. SANDBERG, citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Tractor Excavators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an' extremely simple and highly efficient power-driven combined grader, excavator and load-carrying tractor. To the above ends generally considered, the invention consists of the novel devices and combination of devices hereinafter described and identified in the claims.

The tractor is preferably of the caterpillar type, with laterally spaced treadchains, with a rectangular frame, with an excavating scoop mounted to work within the rectangular frame, and with the motor (preferably an internal combusion engine) mounted on the frame at the rear of the scoop.

The excavating scoop is arranged to be given independent vertical movements or adj ust-Inents at front and rear, so that its angle and elevation may be regulated for picking up a load, for carrying a load and for discharging a load.

The invention is illustrated in the accom panying drawings, wherein like characters indicate like parts throughout the several views. Referring to the drawings:

Fig. 1 is a plan view of the improved machine, which for brevity may be designated as a tractor-excavator; and

Fig. 2 is a side elevation of the same tractor-excavator.

The frame work of the tractor is made up chiefly of laterally spaced side beams 3, a transverse beam 4 and a rear transverse beam 5 which latter is located considerably forward of the rear ends of the side bars. Front wheels 6 are journaled on axles 7 rigidly secured to and projecting outward from the front ends of the side beams 3. The rear wheels 8, likewise are journaled on axles 9 rigidly secured to and projecting outward from the bars of the transverse beam 4:. Wide faced traction belts made up of hinged links are arranged to run over the aligned front and rear wheels; and here it should be noted that the intermediate portions of the side beams 3 are outwardly offset so that they lie in a vertical plane that is between the inner and outer edges of the corresponding traction-belts 10. This offsetting of the beams brings the same intoa position where they may be utilized to support intermediate rollers. for engagement with the inner surface of the respective treadbelts. The lower rollers 11, are journaled to brackets 12, rigidly secured to and depending from the offset portions of the beams 3, and the upper rollers 13 are journaled to brackets 14 secured to the offset portions of said beams 3.

The motor which is preferably a multicylinder internal combustion engine, indicated as an entirety by the numeral 15, is shown as 'mounted on cross-bars 16 rigidly connected across the rear portions of the beams 3. The crank-shaft of this engine is provided with a driving-pinion 17 that meshes with the gear 18 on one end of a transverse countershaft 19, that is 'journaled on suitable bearings onthe rear portions of the bars 3. The shaft 19 is preferably connected through an ordinary or any variable speed transmission mechanism 20. Un the variably driven section of the shaft 19 is a spur-gear 21 that meshes with spur-gear 22, carried by a second transverse counter-shaft 23, journaled in suitable hearings on the rear ends of the frame bars 3. Spurpinions 24 are loosely journaled on the ends of the shaft 23 and these pinions mesh. with internal gears 25, carried by the rear or main tractor wheels 8. On their hubs, the pinions 2% are provided with half-clutches that are adapted to be engaged by clutch-sleeves 26 that rotate with but slide on the shaft 23. These clutchsleeves 26 are adapted to be moved by levers moved and the tractor run upon its wheels 'Z' and 8, but the preferred and best results are obtained by using the traction belts.

Numeral 28 indicates the operators seat which is suitably supported from the rear portion of the tractor.

The excavating scoop 29 is preferably a rectangular structure, provided at its front edge with teeth or projections 30, either formed integral therewith or otherwise applied thereto, to assist in picking up the earth and directing the same into the scoop. This scoop, like other parts of the machine, varies in size, but should be made of a size to carry more than a square yard of earth. The said scoop is arranged to work in the rectangular space formed between the side beams 3 and the front and rear cross-bars 4 and 5. It is capable of independent vertical adjustments at its front and rear portions, but is held against forward and rearward swinging movements by a pair of laterally spaced thrust-bars 31, located outward of but adjacent to the sides of the scoop. These thrust-bars 31 at their rear ends are pivoted on a strong transverse rod 32, the ends of which are rigidly secured to the side beams 3; and the front ends of said thrust-bars 31 are pivoted on the ends of the cross-rod 33 that is located high above the bottom but extended through the sides of the scoop near the front end of the scoop.

For vertically adjusting the front end of the scoop, I preferably provide an upright cylinder and piston air actuated hoist 34, the cylinder of which is mounted on the central portion of the front beam 4: and the piston of which is connected to a cable 35. This cable 35 is passed over the guidesheave 36, journaled to a bracket 37 on the cylinder of the hoist 34:. The free end of the cable 35 is attached to the central portion of the cross-rod 33.

For raising and lowering the rear portion of the scoop 29, I provide an air actuated cylinder and piston hoist 38, the cylinder of which at its lower end is pivotally connected to the cross-beam 5, and the piston of which has an extended depending rod portion 39, that is pivotally connected to a lug on the back of the rear plate of said scoop 29. Compressed air for actuating the hoists 34 and 38 may be delivered to the respective cylinders thereof through any suitable device well known and not necessary for the purposes of this case to consider.

For picking up a load, the scoo will be adjusted into a forwardly incline lowered position, approximately as indicated by dotted lines in Fig. 2, and under forward movement of the tractor, the load will be forced from the ground into the scoop. After the scoop has been filled, it should be set in an approximately horizontal position and raised as shown bythe full lines in Fig. 2. In fact for carrying a load, it will often be desirable to give the scoop a backward inclination.

For dumping the load from the scoop, the scoop should be raised and given the proper forward inclination to cause the dirt to run by gravity from the scoop, and the tractor should usually be backed up while discharging the load; however, there are places where the load may be discharged without backing the tractor, as for example, where the load is to be dumped down a steep embankment. In this latter case, the forward portion of the tractor may be projected oi'er the bank while the scoop is being dumped, inasmuch as the weight of the engine and other parts of the rear portion of the tractor, throw the center of gravity of the machine rearward of its longitudinal center.

A tractor designed as described, may be built at small cost, and has very great strength and durability. By mounting the scoop within the rectangular frame, the construction is cheapened and simplified, and the scoop is placed where it may have absolutely free and independent movements, both at front and rear. Moreover, the ground engaging supports, to wit, as shown, the traction belts are carried both forward and rearward of the scoop, so that a very good base of support is given both for picking up the load and for carrying the load in the scoop.

The connections for operating the pneumatic scoop actuating hoist are not illustrated, nor is it deemed necessary for the purpose of this case to do so, because such operating connections may be of any of the well known arrangements for such purposes hitherto provided for operating similar pneumatic hoists. By what has been said, it will of course be understood that many of the features of this invention may be modified, and that the drawings illustrate what is at present believed to be the preferred arrangement of the general features of the invention.

What I claim is:

1. A tractor having laterally spaced frame beams, front and rear wheels, traction belts running over said front and rear wheels, an engine mounted on the rear portion of the tractor frame and having connections for driving said wheels, in'combination with an excavating scoop located between said frame beams in front of said engine, and independent power devices for independently raising and lowering the front and rear ends of said scoop, said devices each. being connected to said scoop by a single means disposed substantially in the longitudinal center thereof, to thereby move the same bodily in a vertical direction, or to impart angular movements thereto.

2. A tractor having laterally spaced frame beams, front and rear wheels. traction belts running over said front and rear Wheels, an engine mounted on the rear portion of the tractor frame and having connections for driving said wheels, in combination with an excavating scoop located between said frame beams in frontof said engine, and independent cylinder and piston hoisting devices mounted on said tractor, the one serving to raise and lower the front end and the other to raise and lower the rear end of said scoop.

3. A traction scoop comprising a tractor frame having laterally spaced beams, cross beams at the front and rear thereof, a subtending between the side beams at the rear of the scoop, links pivoted thereto at each side of the scoop and extending forwardly to the front of said scoop and being pivoted at their front ends to a rod extending transversely through the scoop above the bottom thereof, an elevating means in the rear of the scoop connected to the center of the rear side thereof, and an elevating means in the front of the scoop connected to the center of said transverse rod.

In testimony whereof I aflixmy signature in presence'of two witnesses.

OLOF S. SANDBERG. \Vitnesses F. D. MERCHANT, HARRY D. KILGORE. 

